1 /** @file
2   Provides services to initialize and process authenticated variables.
3 
4 Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials are licensed and made available under
6 the terms and conditions of the BSD License that accompanies this distribution.
7 The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php.
9 
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12 
13 **/
14 
15 #ifndef _AUTH_VARIABLE_LIB_H_
16 #define _AUTH_VARIABLE_LIB_H_
17 
18 #include <Protocol/VarCheck.h>
19 
20 ///
21 /// Size of AuthInfo prior to the data payload.
22 ///
23 #define AUTHINFO_SIZE ((OFFSET_OF (EFI_VARIABLE_AUTHENTICATION, AuthInfo)) + \
24                        (OFFSET_OF (WIN_CERTIFICATE_UEFI_GUID, CertData)) + \
25                        sizeof (EFI_CERT_BLOCK_RSA_2048_SHA256))
26 
27 #define AUTHINFO2_SIZE(VarAuth2) ((OFFSET_OF (EFI_VARIABLE_AUTHENTICATION_2, AuthInfo)) + \
28                                   (UINTN) ((EFI_VARIABLE_AUTHENTICATION_2 *) (VarAuth2))->AuthInfo.Hdr.dwLength)
29 
30 #define OFFSET_OF_AUTHINFO2_CERT_DATA ((OFFSET_OF (EFI_VARIABLE_AUTHENTICATION_2, AuthInfo)) + \
31                                        (OFFSET_OF (WIN_CERTIFICATE_UEFI_GUID, CertData)))
32 
33 typedef struct {
34   CHAR16        *VariableName;
35   EFI_GUID      *VendorGuid;
36   UINT32        Attributes;
37   UINTN         DataSize;
38   VOID          *Data;
39   UINT32        PubKeyIndex;
40   UINT64        MonotonicCount;
41   EFI_TIME      *TimeStamp;
42 } AUTH_VARIABLE_INFO;
43 
44 /**
45   Finds variable in storage blocks of volatile and non-volatile storage areas.
46 
47   This code finds variable in storage blocks of volatile and non-volatile storage areas.
48   If VariableName is an empty string, then we just return the first
49   qualified variable without comparing VariableName and VendorGuid.
50 
51   @param[in]  VariableName          Name of the variable to be found.
52   @param[in]  VendorGuid            Variable vendor GUID to be found.
53   @param[out] AuthVariableInfo      Pointer to AUTH_VARIABLE_INFO structure for
54                                     output of the variable found.
55 
56   @retval EFI_INVALID_PARAMETER     If VariableName is not an empty string,
57                                     while VendorGuid is NULL.
58   @retval EFI_SUCCESS               Variable successfully found.
59   @retval EFI_NOT_FOUND             Variable not found
60 
61 **/
62 typedef
63 EFI_STATUS
64 (EFIAPI *AUTH_VAR_LIB_FIND_VARIABLE) (
65   IN  CHAR16                *VariableName,
66   IN  EFI_GUID              *VendorGuid,
67   OUT AUTH_VARIABLE_INFO    *AuthVariableInfo
68   );
69 
70 /**
71   Finds next variable in storage blocks of volatile and non-volatile storage areas.
72 
73   This code finds next variable in storage blocks of volatile and non-volatile storage areas.
74   If VariableName is an empty string, then we just return the first
75   qualified variable without comparing VariableName and VendorGuid.
76 
77   @param[in]  VariableName          Name of the variable to be found.
78   @param[in]  VendorGuid            Variable vendor GUID to be found.
79   @param[out] AuthVariableInfo      Pointer to AUTH_VARIABLE_INFO structure for
80                                     output of the next variable.
81 
82   @retval EFI_INVALID_PARAMETER     If VariableName is not an empty string,
83                                     while VendorGuid is NULL.
84   @retval EFI_SUCCESS               Variable successfully found.
85   @retval EFI_NOT_FOUND             Variable not found
86 
87 **/
88 typedef
89 EFI_STATUS
90 (EFIAPI *AUTH_VAR_LIB_FIND_NEXT_VARIABLE) (
91   IN  CHAR16                *VariableName,
92   IN  EFI_GUID              *VendorGuid,
93   OUT AUTH_VARIABLE_INFO    *AuthVariableInfo
94   );
95 
96 /**
97   Update the variable region with Variable information.
98 
99   @param[in] AuthVariableInfo       Pointer AUTH_VARIABLE_INFO structure for
100                                     input of the variable.
101 
102   @retval EFI_SUCCESS               The update operation is success.
103   @retval EFI_INVALID_PARAMETER     Invalid parameter.
104   @retval EFI_WRITE_PROTECTED       Variable is write-protected.
105   @retval EFI_OUT_OF_RESOURCES      There is not enough resource.
106 
107 **/
108 typedef
109 EFI_STATUS
110 (EFIAPI *AUTH_VAR_LIB_UPDATE_VARIABLE) (
111   IN AUTH_VARIABLE_INFO     *AuthVariableInfo
112   );
113 
114 /**
115   Get scratch buffer.
116 
117   @param[in, out] ScratchBufferSize Scratch buffer size. If input size is greater than
118                                     the maximum supported buffer size, this value contains
119                                     the maximum supported buffer size as output.
120   @param[out]     ScratchBuffer     Pointer to scratch buffer address.
121 
122   @retval EFI_SUCCESS       Get scratch buffer successfully.
123   @retval EFI_UNSUPPORTED   If input size is greater than the maximum supported buffer size.
124 
125 **/
126 typedef
127 EFI_STATUS
128 (EFIAPI *AUTH_VAR_LIB_GET_SCRATCH_BUFFER) (
129   IN OUT UINTN      *ScratchBufferSize,
130   OUT    VOID       **ScratchBuffer
131   );
132 
133 /**
134   This function is to check if the remaining variable space is enough to set
135   all Variables from argument list successfully. The purpose of the check
136   is to keep the consistency of the Variables to be in variable storage.
137 
138   Note: Variables are assumed to be in same storage.
139   The set sequence of Variables will be same with the sequence of VariableEntry from argument list,
140   so follow the argument sequence to check the Variables.
141 
142   @param[in] Attributes         Variable attributes for Variable entries.
143   @param ...                    The variable argument list with type VARIABLE_ENTRY_CONSISTENCY *.
144                                 A NULL terminates the list. The VariableSize of
145                                 VARIABLE_ENTRY_CONSISTENCY is the variable data size as input.
146                                 It will be changed to variable total size as output.
147 
148   @retval TRUE                  Have enough variable space to set the Variables successfully.
149   @retval FALSE                 No enough variable space to set the Variables successfully.
150 
151 **/
152 typedef
153 BOOLEAN
154 (EFIAPI *AUTH_VAR_LIB_CHECK_REMAINING_SPACE) (
155   IN UINT32                     Attributes,
156   ...
157   );
158 
159 /**
160   Return TRUE if at OS runtime.
161 
162   @retval TRUE If at OS runtime.
163   @retval FALSE If at boot time.
164 
165 **/
166 typedef
167 BOOLEAN
168 (EFIAPI *AUTH_VAR_LIB_AT_RUNTIME) (
169   VOID
170   );
171 
172 #define AUTH_VAR_LIB_CONTEXT_IN_STRUCT_VERSION  0x01
173 
174 typedef struct {
175   UINTN                                 StructVersion;
176   UINTN                                 StructSize;
177   //
178   // Reflect the overhead associated with the saving
179   // of a single EFI authenticated variable with the exception
180   // of the overhead associated with the length
181   // of the string name of the EFI variable.
182   //
183   UINTN                                 MaxAuthVariableSize;
184   AUTH_VAR_LIB_FIND_VARIABLE            FindVariable;
185   AUTH_VAR_LIB_FIND_NEXT_VARIABLE       FindNextVariable;
186   AUTH_VAR_LIB_UPDATE_VARIABLE          UpdateVariable;
187   AUTH_VAR_LIB_GET_SCRATCH_BUFFER       GetScratchBuffer;
188   AUTH_VAR_LIB_CHECK_REMAINING_SPACE    CheckRemainingSpaceForConsistency;
189   AUTH_VAR_LIB_AT_RUNTIME               AtRuntime;
190 } AUTH_VAR_LIB_CONTEXT_IN;
191 
192 #define AUTH_VAR_LIB_CONTEXT_OUT_STRUCT_VERSION 0x01
193 
194 typedef struct {
195   UINTN                                 StructVersion;
196   UINTN                                 StructSize;
197   //
198   // Caller needs to set variable property for the variables.
199   //
200   VARIABLE_ENTRY_PROPERTY               *AuthVarEntry;
201   UINTN                                 AuthVarEntryCount;
202   //
203   // Caller needs to ConvertPointer() for the pointers.
204   //
205   VOID                                  ***AddressPointer;
206   UINTN                                 AddressPointerCount;
207 } AUTH_VAR_LIB_CONTEXT_OUT;
208 
209 /**
210   Initialization for authenticated varibale services.
211   If this initialization returns error status, other APIs will not work
212   and expect to be not called then.
213 
214   @param[in]  AuthVarLibContextIn   Pointer to input auth variable lib context.
215   @param[out] AuthVarLibContextOut  Pointer to output auth variable lib context.
216 
217   @retval EFI_SUCCESS               Function successfully executed.
218   @retval EFI_INVALID_PARAMETER     If AuthVarLibContextIn == NULL or AuthVarLibContextOut == NULL.
219   @retval EFI_OUT_OF_RESOURCES      Fail to allocate enough resource.
220   @retval EFI_UNSUPPORTED           Unsupported to process authenticated variable.
221 
222 **/
223 EFI_STATUS
224 EFIAPI
225 AuthVariableLibInitialize (
226   IN  AUTH_VAR_LIB_CONTEXT_IN   *AuthVarLibContextIn,
227   OUT AUTH_VAR_LIB_CONTEXT_OUT  *AuthVarLibContextOut
228   );
229 
230 /**
231   Process variable with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS/EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set.
232 
233   @param[in] VariableName           Name of the variable.
234   @param[in] VendorGuid             Variable vendor GUID.
235   @param[in] Data                   Data pointer.
236   @param[in] DataSize               Size of Data.
237   @param[in] Attributes             Attribute value of the variable.
238 
239   @retval EFI_SUCCESS               The firmware has successfully stored the variable and its data as
240                                     defined by the Attributes.
241   @retval EFI_INVALID_PARAMETER     Invalid parameter.
242   @retval EFI_WRITE_PROTECTED       Variable is write-protected.
243   @retval EFI_OUT_OF_RESOURCES      There is not enough resource.
244   @retval EFI_SECURITY_VIOLATION    The variable is with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
245                                     or EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACESS
246                                     set, but the AuthInfo does NOT pass the validation
247                                     check carried out by the firmware.
248   @retval EFI_UNSUPPORTED           Unsupported to process authenticated variable.
249 
250 **/
251 EFI_STATUS
252 EFIAPI
253 AuthVariableLibProcessVariable (
254   IN CHAR16         *VariableName,
255   IN EFI_GUID       *VendorGuid,
256   IN VOID           *Data,
257   IN UINTN          DataSize,
258   IN UINT32         Attributes
259   );
260 
261 #endif
262